Hydrocarbon conversion method

ABSTRACT

A METHOD FOR PREPARING CRYSTALLINE ALUMINOSILICATE ZEOLITE CATALYSTS HAVING A LOW ALKALI METAL CONTENT IS THE ZECLITE AND CONTAINING (1) A POLYVALENT METAL CATION, PREFERABLY AN ION GROUP METAL SND (2) A HYDROGENATION COMPONENT, COMPRISES PRE-CALCINING OR PRE-STEAMING THE POLYVALENT METAL CONTAINING ZEOLITE TO ADDITION OF THE HYDROGENATION COMPONENT. THE INVENTION ALSO INCLUDES THE SUBSEQUENT INTRODUCTION OF ADDITIONAL STABILIZING ELEMENT FOLLOWING THE PRE-CALCINING OR PRE-STEAMING BUT PRIOR TO ADDITION OF THE HYDROGENATION COMPONENT. THE CATALYSTS FIND PARTICULAR UTILITY IN HYDROCRACKNG AND HYDROTREATING PROCESSES.

United States Patent 3,766,056 HYDROCARBON CUNVERMUN WTHUD Dean ArthurYoung, Yorha Linda, Califtl, assignor to Union Oil Company ol?California, lLos Angeles, (Ialif. No Drawing. Application Mar. 9, 1970,Ser. No. 17,974,

now Patent No. 3,706,694, which is a continuation-inpart of abandonedapplication Ser. No. 761,321, Sept.

20, 1968, which in turn is a contiuuation-in-part of abandonedapplication Ser. No. 681,561, Nov. 8, 1967.

Divided and this application iuly ]l7 1972, Ser. No.

Int. Cl. Cllilg 13/02; Cllllb 33/28 US. Cl. 208 11l 6 Claims ABSTRACT01F THE DIISCLUSURE This application is a divisional application of SN17,974 filed Mar. 9, 1970 (now US. Pat. 3,706,694), acontinuation-in-part of application Ser. No. 761,321, filed Sept. 20,1968, now abandoned which was a continuation-in-part of Ser. No.681,561, filed Nov. 8, 1967, now abandoned.

This invention concerns the preparation of crystalline zeolite catalystshaving improved activity and stability. Improved stability is evidencedby the retention of a larger proportion of the original structure of thezeolite after successive hydrations and recalcinations. This stabilityis desirable in catalysts which are subjected to regenerations, attackby anionic or acid-forming elements, and contact with ions which removedesirable cations from the zeolite structure. For example, addition ofhydrogenation components such as molybdenum and tungsten tends to have adestabilizing effect on the catalyst structure.

Zeolites having low, i.e., less than about 3 percent, alkali metalcontent are conventionally prepared by conversion of the alkali metalform of the zeolite to the ammonium form. This ammonium form is thenconverted to the hydrogen form by calcination. It is well known that thehydrogen forms of zeolites, such as synthetic types A, X and Y, areunstable, the crystalline structures being destroyed by calcination,rehydration, and contact with acidic solutions. I have found thatcatalysts prepared with these zeolites should contain at least onepolyvalent metal cation, preferably iron, cobalt or nickel. Although theexact mechanisms by which these cations improve the properties of thesecatalysts are not known with certainty it is believed that theirpresence tends to stabilize the resultant compositions, i.e., renderthem less susceptible to degradation, as well as contribute to theactivity, particularly the hydrogenation activity of the finished cata--lyst.

It has now been found that the stability and activity of such zeolitecatalysts may be substantially increased by calcination or steamingafter addition of the polyvalent metal cation but prior to addition ofthe hydrogenation component.

It is believed that the permanent stabilization of the invention mayrelate to two effects. Thermal activation may cause the polyvalent metalcation to become attached to normally inaccessible sites where it is notreplaced by other cations. Secondly, calcination dehydrates the cationand the anionic exchange sites causing the formation of directmetal-oxygen-aluminum bonds. It is believed that this combination withthe stabilizing element is not readily hydrolyzed. Consequently, thestabilizing cation becomes fixed in the zeolite structure and thecombination resists hydrolysis and exchange.

Crystalline aluminosilicate zeolites are conventional and include thenatural zeolites faujasite, mordenite, erionite and chabazite andsynthetic zeolites A, L, S, T, X and Y. Zeolites X, Y and L aredescribed in US. Pats. 2,882,244; 3,130,077 and 3,216,789. Thesecrystalline zeolites are metal aluminosilicates having a crystallinestructure such that a relatively large adsorption area is present insideeach crystal. They consist basically of three-dimensional frameworks ofSiO., and A10 tetrahedra with the tetrahedra cross-linked by the sharingof oxygen atoms. The electrovalence of the tetrahedra containingaluminum is balanced by the inclusion in the crystal of cations, forexample, metal ions, ammonium ions, amine complexes, or hydrogen ions.The spaces in the pores may be occupied by water or other adsorbatemolecules.

Normally, the crystalline zeolites occur, or are prepared, in the sodiumor potassium form. The ammonium form of the zeolite is prepared by ionexchange of the sodium or potassium form with an ammonium salt toreplace most or all of the sodium or potassium. This procedure forpreparation of the ammonium form of zeolites is also conventional and isdescribed in US. Pat. No. 3,130,006.

The zeolites presently preferred for application within the concept ofthis invention are those having relatively large pore sizes, i.e., 5angstroms or greater, generally characterized as being sufiicient toadmit the ingress and egress of isoparaffins to and from the interior ofthe zeolite. Illustrative of zeolites within this class are zeolites L,T, X, Y, mordenite, and the like. The desirability of employing largerpore size zeolites derives from the improved product distributions whichresult from their use, particularly in hydrocracking applications.Understandably the larger pore openings facilitate the migration oflarger hyrocarbon molecules into the zeolite. The natural and syntheticfaujasite type zeolites, e.g., zeolites X and Y are presentlyparticularly preferred.

The polyvalent metal cations employed within the concept of thisinvention are preferably selected from the biand trivalent metalcations, particularly iron, cobalt, nickel, magnesium, calcium,manganese and the rare earth metals, i.e., the metals of the lanthanideseries, par ticularly cerium, lanthanum, praseodymium and neodymium.Zeolites can contain any one or a cormbination of these cations prior tocalcination. The cations presently particularly preferred are the irongroup metals, especially cobalt and nickel due to the improvements instability and activity occasioned by the use of these cations. It ispresently preferred that these cations be incorporated into the ammoniumor hydrogen form of the zeolite, i.e., after exchange of the alkalimetal form of the zeolite with ammoniacal or mildly acidic solutionsand/or partial calcination of the ammonium form sufiicient to convertthe same to the corresponding hydrogen form. Nevertheless, they can alsobe incorporated directly into the alkali metal form of the zeolite byconventional exchange procedures.

The polyvalent metal cations are generally incorporated into theammonium or hydrogen form of the zeolite in the form of a cation usingconventional exchange procedures. They can be incorporated bybase-exchange with an aqueous solution of the metal salt or a suitablecationic complex such as the tetramine or hexamine. Suitable salts are,e.g., nitrates, acetates, carbonates,

chlorides, bromides and sulfates. The base exchange is conducted for aperiod of time and at a temperature suitable to replace at least 20percent, preferably at least about 50 percent, of the ammonium or alkalimetal cations of the zeolite. Proportions of these cations will rangefrom about 2 to 15 percent by weight, preferably about 4 to 8 percentdetermined as the corresponding oxides. Following this exchange theproduct may be predried or directly transferred to the calcination orsteaming vessel.

The polyvalent cation containing zeolite is then stabilized by calciningor steaming at a temperature of from about 500 to 1800 F., for a periodof about /2 to 30 hours, preferably about 4 to 16 hours. Calcination maybe effected in air or oxygen alone or mixed with water vapor. Whensteaming is employed the zeolite is treated with about 2 to 20 p.s.i.a.steam, which may be either static or passed in a stream over thezeolite. The preferred temperature for steaming is about 900 to 1200 F.

Calcination, i.e., heating to elevated temperature in the substantialabsence of water vapor, has generally been found to give resultssuperior to those obtained by steaming. The preferred temperature forcalcination is from about 1200 to 1800 F. Optimum calcinationtemperature within this approximate range will vary with the type ofzeolite base, the specific cationic form and hydrogenation componentemployed, the type of reaction in which the catalyst is employed, etc.,and is best determined experimentally. Generally, however, it has beenfound that calcination below, but within about 100 to 200 F. of, thedecomposition temperature of the zeolite gives best results.

In addition, it has been found that a two-step calcination procedure mayeven further enhance the activity of the catalysts. In this procedurethe exchanged zeolite is first calcined at a temperature of about 600 toabout 1300" F. and is then further calcined at a higher temperature ofabout 1400 to about 1800 F., with or Without cooling between thesuccessive calcinations. In addition, the exchanged zeolite can becalcined or steamed as described followed by further exchange with thesame or a similar cation of the prescribed class of polyvalent cationsto increase the cation concentration of the zeolite and reduce thealkali metal content thereof while enhancing the activity and stabilityof the resultant compositions. Multiple exchange-calcination cycles ofthis nature can be employed if desired.

The hydrogenation components include the metals, oxides and sulfides ofGroups V, VI and VIII of the Periodic Table. Specific examples includevanadium, chromium, molybdenum, tungsten, iron, cobalt, nickel,platinum, palladium and rhodium or any combination of these metals ortheir oxides or sulfides. The Group VI metals, oxides and sulfides arepresently preferred, particularly in midbarrel hydrocrackingapplications, the molybdenum and tungsten derivatives being mostpreferred due to their superior activity. Amounts of the hydrogenationcomponent will usually range from about 0.1% to 20% by weight of thefinal composition based on free metal. Generally, optimum proportions ofthe Group V and VI metals and compounds will range from about 2 to 20%.Molybdenum in the form of the sulfide is especially preferred as thehydrogenation component. When a metal of the platinum series isemployed, the amount thereof will generally range from about 0.01 to 5weight percent, preferably 0.1 to 2 weight percent based on the freemetal.

It has also been found that the stability and activity of the catalystmay be improved by the addition of further amounts of the same ordissimilar cations follow ing the pretreatment, i.e., following thecalcining, steaming, or both. This addition is accomplished in the samemanner as the initial incorporation of the stabilizing element, i.e., bymeans of the conventional exchange procedures described above. Theexchange is conducted for a period of time and at a temperaturesufiicient to replace about 30 to percent of the alkali metal and/orhydrogen ions remaining in the zeolite. The resultant zeolite willcontain from about 2 to 15, preferably 4 to 8 percent by Weight of thepolyvalent cation determined as the corresponding oxide. Following thisadditional exchange the product is dried, or dried and calcined, priorto addition of the hydrogenation component.

Following calcination of the polyvalyent cation form of the zeolite, andeither before or after inclusion of the Group VIII or Group VI metalhydrogenation component, the zeolite can be formed into a particulateform by extrusion or pelleting suitable for the intended application.Ion exchange of the zeolite is preferably accomplished when the zeoliteis in a finely dispersed powder form so as to facilitate mass transfer.Similar considerations may also be taken into account when designingprocedures for incorporating the additional hydrogenation components,i.e., the Group VI and Group VIII metals, oxides, or sulfides. As ageneral rule, if these latter constituents are also to be incorporatedby ion exchange, such exchange is also preferably effected while thezeolite is in a finely dispersed powder form. Nevertheless, thesehydrogenation components can be added by mechanical admixture withinsoluble forms of those components after fabrication of the zeolitepowder into larger particulate forms. In any event, the resultant powdercomposite is preferably either pelleted or extruded to produce catalystparticles of the desired shape, size, density and structural stability.For application in most hydrocarbon conversion processes, e.g.,hydrocracking, cracking, hydrofining, isomerization, reforming,hydrogenation and the like, catalyst extrudates or pellets are generallysuitable.

Due to the generally inferior binding properties of zeolites alone, itis usually preferred to incorporate into the zeolite powder about 5 toabout 40 weight percent of a binding agent such as alumina orsilica-stabilized alumina preferably introduced as a form of a hydrogelor sol. However, mixed oxides such as silica-alumina, silicamagnesia orthe like, are also suitable for these purposes. Binders of this natureare discussed in more detail in the prior art exemplified by BritishPat. 1,056,301.

The advantages of this invention are not limited to compositionscomprising predominantly the zeolite constituent of the resultingcombination. The zeolite may comprise only a minor proportion of thefinal combination. For example, active compositions may contain aslittle as about 2 weight percent of the zeolite. The catalyticproperties of these latter compositions will of course deviate fromthose of the compositions containing higher amounts of zeolites. Forexample, compositions containing minor amounts of these zeolites willexhibit a lower preference for gasoline range hydrocarbons and a higherselectivity for midbarrel range fuels. They will also exhibit loweroverall degrees of hydrocracking in low severity operations wherein theprimary objective is hydrofining, e.g., denitrogenation anddesulfurization.

The catalyst pellets are then dried and activated by calcining in anatmosphere that does not adversely afiect the catalyst, such as air,nitrogen, hydrogen, helium, etc. Generally, the dried material is heatedin a stream of dry air at a temperature of from about 500 F. to 1500 F.,preferably abeut 900 F., for a period of from about V2 to 12 hours,preferably about 2 hours, thereby converting the metal constituents tooxides and converting the ammonium zeolite to the hydrogen form.

In addition, the catalysts are preferably further activated bypresulfiding with a sulfur donor such as hydrogen sulfide, carbondisulfide, elemental sulfur and hydrocarbon thiols and thioethers toconvert the metal constituents of the catalyst to the correspondingsulfides. This is readily accomplished, e.g., by saturating the catalystpellets with hydrogen sulfide for a period of from about 30 minutes to 2hours. These procedures are described in more detail in US. Pat.3,239,451.

The feedstocks which may be treated using the catalyst of the inventioninclude in general any mineral oil fraction boiling above about 200 F.,usually above the conventional gasoline range, i.e., about 300 F., andgenerally above about 400 F. The end boiling points of such feedsusually range up to about 1200 F. Exemplary of such feeds are straightrun gas oils, light and heavy naphthas, coker distillate gas oils,reduced crude oils, cycle oil derived from catalytic or thermal crackingoperations, topped crudes, etc. These fractions may be derived frompetroleum crude oils, shale oils, tar sand oils, coal hydrogenationproducts, and the like. Any of these hydrocarbons or mixtures thereofcontaining sulfurous or nitrogenous hydrocarbons can be employed inprocesses utilizing the catalyst of this invention to effect hydrofiningof those feeds. However, feedstocks most commonly employed inhydrofining and hydrocracking operations are those boiling above about400 F. and up to about 1200 F., usually up to about 1000 F. having APIgravities within the range of about 20 to about 35. The concentration ofacid soluble constituents, e.g., aromatics and olefins, in suchhydrocracker feedstocks is usually in excess of about 30 volume percent.

Hydrocarbons can be converted by contacting with the catalyst of thisinvention under a wide variety of conditions in either fixed bed orfluid catalytic systems. Contacting temperatures are usually within therange of 500 to 900 F., preferably about 6 50 to about 850 F. Thislatter narrower temperature range is particularly attractive for theproduction of gasoline and midbarrel range hydrocarbons in hydrocrackingsystems. When hydrocracking is the preferred reaction, pressures shouldbe relatively elevated, i.e., within the range of about 1000 to about3000 p.s.i.g., preferably 1500 to about 2500 p.s.i.g., and the reactionshould be conducted at liquid hourly space velocities Within the rangeof about 0.1 to about 10, preferably 0.2 to about 5, in the presence ofhydrogen added at a rate of at least about 500, and preferably about5000 to 15,000 standard cubic feed per barrel of feed. Less severeconditions should be employed when it is desirable to effect primarilyhydrofining while minimizing the degree of molecular weight reductionattributable to hydrocracking. However, the most favorable hydrofiningconditions fall within the ranges described above. The most desirablebalance of these two conversion mechanisms, i.e., hydrofining andhydrocracking, will also be affected, in degree, by the characteristicsof the feedstock employed and can be best determined empirically simplyby operating at several sets of conditions and analyzing the resultantproducts.

A particularly attractive catalyst envisioned in the scope of thisinvention can be prepared by exchanging an ammonium zeolite Y with anexcess of a solution of one or both of cobalt or nickel salts such asthe nitrates, sulfates and carbonates, the nitrates being particularlypreferred, under conditions sufiicient to incorporate at least about 0.5weight percent of the corresponding metal compound into thealuminosilicate based on the weight of the corresponding element. Thiscan be conveniently effected by contacting the aluminosilicate,preferably containing less than 2 weight percent of the original alkalimetal based on the corresponding oxide, with at least a two-fold excessof exchange solution having at least a 0.1 molar, preferably 0.2 to 3molar concentration of the selected metal salt. The term excess solutionis herein intended to mean that the amount of solution employed shouldbe at least about twice that of the bulk volume of the aluminosilicatetreated. Contacting should be continued for at least about 5, preferablyat least about 20 minutes with agitation to assure adequate contactingof the aluminosilicate with the exchange solution. The exchange reactioncan also be accelerated by contacting at elevated temperatures, i.e., upto about 200 F. Higher temperatures can, of course, be employed if it isnot inconvenient to opcrate the system under pressure. However,temperatures substantially above this level are not necessary in theprocedure.

It is presently perferred that the exchange procedure be repeated atleast once to effect the further removal of al kali metal and ammoniumcations from the aluminosilicate and the substitution of cobalt and/ornickel therefor. Three or more exchanges of this nature can also beemployed. After each exchange, the aluminosilicate is preferably washedfree of exchange solution prior to contacting with the next changemedium. The zeolite can also be subjected to calcination intermediatethe exchange steps.

In this preferred procedure the calcined aluminosilicate is thenmechanically admixed with additional substantially undissolved nickeland/or cobalt in the form of a thermally decomposable salt thereof suchas nickel carbonate, cobalt nitrate, nickel sulfate and the like inaddition to a thermally decomposable molybdenum compound such asammonium heptamolybdate, ammonium phosphomolybdate, molybdenum trioxideand the like, under conditions such that the molybdenum compound isrelatively insoluble, i.e., in the absence of substantial amounts ofwater. The amount of added nickel, cobalt and molybdenum compoundsshould be sufiicient to provide a finished catalyst containing about 2to about 15, preferably about 4 to about 8 weight percent of thecorresponding nickel and/ or cobalt oxides, and about 2 to about 20weight percent molybdenum oxide.

It is also preferable to incorporate at least about 2, and preferablyabout 5 to about 70 weight percent, generally about 5 to about 30 weightpercent of a peptized alumina or silica stabilized alumina binder.Peptized alumina binders are generally well known in the art for bindingaluminosilicate compositions and are readily prepared by exposing thealumina to a mildly acidic solution of a strong mineral acid such asnitric or sulfuric acids and the like for a period of at least about 5minutes.

The combined constituents, i.e., the aluminosilicate, peptized aluminabinder, and added metal compounds are mechanically admixed, for example,in a pan muller, for a period sufiicient to effect the intimateadmixture of all of these constituents, i.e., at least about 10 minutes,preferably about 15 minutes to about 1 hour. The resultant combinationis then formed into the desired shape by either extrusion or pelleting.The extrudates or pellets are then dried and calcined at a temperaturepreferably within the range of 500 to 1500 F. in the presence of anoxidizing atmosphere for a period sufiicient to convert the metalconstituents to the corresponding oxides. The resultant calcinedcatalyst is then sulfided by contacting preferably with hydrogen sulfideor carbon bisulfide either prior to introduction into the conversionunit or in situ in the unit.

The process of this invention may be carried out in any equipmentsuitable for catalytic operations. It may be operated batchwise orcontinuously. Accordingly, the process is adapted to operations using afixed bed of catalyst. Also, the process can be operated using a movingbed of catalyst wherein the hydrocarbon flow may be concurrent orcountercurrent to the catalyst flow. A fluidtype of operation may alsobe employed. After hydrocracking, the resulting products may beseparated from the remaining components by conventional means such asadsorption or distillation. Also, the catalyst after use over anextended period of time may be regenerated in accordance withconventional procedures by burning off carbon in an oxygen-containingatmosphere under conditions of elevated temperature.

While the foregoing description has centered mainly upon hydrocrackingor hydrotreating processes, the catalysts described are also useful in avariety of other chemical conversions, and generally, in any catalyticprocess requiring a hydrogenating and/or acid function in the catalyst.Examples of other reactions contemplated are hydrogenation, alkylation(of isoparaffins with olefins, or of aromatics with olefins, alcohols oralkyl halides),

isomerization, polymerization, reforming (hydroforming) carbonylation,hydrodealkylation, hydration of olefins, transalkylation, etc.

The following examples will serve to more particularly illustrate thepreparation of the catalysts of this invention and their advantageousproperties in hydrocracking operations.

EXAMPLES 1-4 A cobalt zeolite Y was prepared as follows:

Ammonium zeolite Y, 2100 g. containing 1.8% Na O, was slurried in 2000ml. 0.5 M Co(NO The slurry was stirred and heated to boiling for twohours. Then the zeolite was collected by filtration and washed with 1000ml. water. The exchange and washing were repeated three times. Then thecobalt zeolite was dried to 31.7% moisture.

Four catalyst bases were then prepared by treatment of 293 g. portionsof the thus-prepared cobalt zeolite Y according to the followingexamples:

Example 1: Cobalt zeolite Y was dried 16 hours at 140 F.

Example 2: Cobalt zeolite Y was dried 16 hours at 140 F. and then heatedto 500 F. for 6 hours.

Example 3: Cobalt zeolite Y was dried 16 hours at 140 F., heated to 500F. for 6 hours, and then heated to 1200 F. for 6 hours.

Example 4: Cobalt zeolite Y was dried 16 hours at 140 F., heated to 500F. for 6 hours, and then heated to 900 F. in an atmosphere of steam for16 hours.

:An alumina binder for the catalysts was prepared as follows:

Boehmite alumina, containing 22% moisture, was mixed with 0.15 N HNO Theproportions were 525 g.

alumina in 1215 ml. acid. The mixture was aged over- The mixture was drymulled for 30 minutes. Then a 343 g. portion of the boehmite alumina solwas added and mulling continued until the mixture appeared uniform.Finally, sufficient water was added to form an extrudable paste. Thefollowing list gives the quantities of water added to each preparationprior to extrusion:

Example: M1. 1 None The mulled pastes were extruded as A -inch diameterrod and dried overnight at room temperature. The extrudates were brokeninto A; to A-inch lengths and then dried 2 hours at 220 F. The catalystswere then activated by heating in a rotary calciner according to thefollowing schedule:

Hours 500 to 600 F 2 600 to 800 F 2 800 to 875 F 2 Crystallinestabilities were determined by measuring the summed intensities of theX-ray diffraction patterns before calcining (activating) and aftercalcining, rehydrating and recalcining at 1000 F. Table 1 compares thefractions of original structure remaining after this severe treatment.

The above data show that precalcining or steaming the cobalt zeolitebase appreciably improved the hydrothermal stability of the finalpreparation.

The catalysts of Examples 1, 3 and 4 were saturated with hydrogensulfide at room temperature for a period of 2 hours and then tested forcatalytic activity by hydrocracking a synthetic gas oil having thefollowing properties:

Gravity APL- 24.6 Boiling range F..- 400-812 Sulfur content wt. percent"1.0

The test conditions were: 650 F.; 1000 p.s.i.g.; 2.0 LHSV; 6000 c.f. H/b. Product collected during 26-42 hours on stream was distilled todetermine the yields of -340 F. boiling gasoline. Results are shown inTable 2.

TABLE 2 Catalyst of Catalyst 120-340 F. Example preparation gasolineyield 1 Dried, F 13.9 vol. percent feed. 3 Calcined, 1,200" F 26.3 vol.percent feed. 4 Steamed, 900 F 24.4 vol. percent feed.

The above data show that precalcining or presteaming the zeolite basesubstantially improved the catalyst activity.

EXAMPLE 5 This example illustrates the effectiveness of the method ofthe invention for making catalysts for use in hydrotreating.

A cobalt hydrogen .zeolite Y containing 6 percent CO0 was heated to 1300F. in 3 hours and held at that temperature for 16 hours. It was thenmulled Wth 61.9 g. Ni(NO -6H O (25.7% NiO) and 14.3 g. NiCO (57.3% NiO)until a uniform powder formed. Then 92 g. (NH Mo-;O -4H O (82% M00 wasadded and mulling was continued to mix uniformly. Finally, a boehmitepaste, 385 g. (26% A1 0 was added with sufiicient water to form anextrudable paste. The boehmite paste contained about 0.8 me. nitric acidper gram of A1 0 as a peptizing agent. The final mulled mixture wasextruded through a yig-iIlCh die, dried and calcined by heating to 870F.

The catalyst was tested with a straight run gas oil feed having thefollowing properties:

The reactor charge was presulfided with a stream of 10% hydrogen sulfidein hydrogen while heating from room temperature to 700 F. Then thereactor was pressured to 1000 p.s.i.g. prior to introducing the feed.The temperature remained at 700 F. for 18 hours and then was increasedto 740 F. for the next 3 days. Pressure, feed rate, and hydrogen rateremained constant at 1000 p.s.i.g., 1.0 LHSV, and 6000 standard cubicfeet of hydrogen per barrel. Data from the test showed values ofresidual nitrogen and sulfur in the 500+ distillation bottoms fractionof 0.008 and 0.0095, respectively, thus indicating the highly effectivenature of the catalyst for denitrogenation and desulfurization.

EXAMPLE 6 This example illustrates a method which can be used for thepreparation of a catalyst encompassed within the scope of this inventioncontaining rare earth backexchanged ammonium zeolite X, nickel andmolybdenum.

Two thousand grams of the sodium zeolite X containing about 20 molepercent Na O, 23 mole percent A1 and 56 mole percent SiO can be slurriedwith 2000 milliliters of an aqueous exchange solution at a pH of about 4containing 1.5 pounds of the chlorides of cerium and lanthanum underagitation to improve contacting. The slurry is stirred and heated toabout 200 F. for 2 hours. The zeolite is then collected by filtration,washed with deionized distilled water and subjected to further exchangewith fresh exchange solution as described above. The exchange isrepeated for a third time after which the resultant rare earth zeoliteX, which should contain less than 2 weight-percent Na 'O, is collectedby filtration, dried by contacting at 250 F. for 2 hours and calcined byheating to 900 F. The calcined zeolite is then mechanically admixed withgrams of nickel carbonate, 41 grams of nickel nitrate hexahydrate and 61grams of ammonium molybdate in a pan muller for about 30 minutes. Thepeptized boehmite alumina described in Examples 1 through 4 (320 grams)is then added and the mulling is continued for an additional 30 minutes.About 30 milliliters of water is added to form an extrudable paste andthe mixture is extruded through a ;-inch die, dried at 200 F. for 2hours and calcined at 800 F. for 1 hour.

The resultant extrudates are then contacted with a stream of 10 percenthydrogen sulfide in hydrogen at atmospheric pressure of 200 F. for 2hours to substantially sulfide the nickel and molybdenum.

EXAMPLE 7 A catalyst similar to that described in Example 6 can Theprepared from magnesium zeolite L. Sodium zeolite L is subjected to theammonium exchange procedures described in Example 6 after which theammonium zeolite containing less than 2 weight-percent Na O on a dryweight basis is recovered by filtration and dried at 200 F. for 1 hourand calcined by heating to 900 The calcined zeolite is then reexchangedwith 2000 milliliters of fresh exchange solution having a 0.5 molarconcentration of magnesium sulfate under agitation at 200 F. for 2hours. The resultant zeolite is again separated by filtration andcalcined as described and subjected to one additional exchange asdescribed. Following the last exchange step the zeolite is dried at 250F. for 2 hours and calcined by heating to 900 F. The dried zeolite isthen mechanically admixed with undissolved constituents as follows, 10grams of nickel carbonate, 45 grams of cobalt nitrate, and '60 grams ofammonium heptamolybdate. Mixing in a pan muller is continued for 30minutes after which 320 grams of the peptized boehmite alumina soldescribed in Examples 1 through 4 is added to the muller. Mulling iscontinued for an additional 30 minutes until the mixture is renderedhomogeneous. Thirty milliliters of water are added to the mixture toform an extrudable paste and the resultant paste is extruded through a-inch die, dried and calcined as described in Example 6. The calcinedextrudates are then contacted at 100 F. with a solution of 2% carbonbisulfide in kerosene 10 passed over to the catalyst at a rate of 0.2LHSV for 2 hours to form an active sulfided catalyst.

EXAMPLE 8 An active hydrocracking catalyst can be prepared from rareearth zeolite Y within the scope of this invention as follows: The rareearth zeolite Y is prepared by contacting sodium zeolite Y withammoniacal exchange solution as described in Example 6. The resultantammonium form of the zeolite Y containing less than 2 weight-percent Na'O is then exchanged as described in Example 6 with an exchange solutioncontaining the chlorides of cerium and lanthanium. As described inExample 6, the ammonium zeolite Y is exchanged three times with the rareearth exchange solution with the exception that the zeolite is calcinedintermediate each exchange step. This calcination can be effected byseparating the exchanged zeolite from the supernatant exchange medium byfiltration, drying at 200 F. for 2 hours and calcining by heating to 900F. The rate earth back exchanged Y zeolite is then finally dried at 250for 2 hours and calcined by heating to 900 F. The calcined zeolite isthen mechanically admixed with nickel, cobalt and molybdenum asdescribed in Example 7 and sulfided by contacting with a stream of 10%hydrogen sulfide in hydrogen at F. for 2 hours to form an activesulfided catalyst.

I claim:

1. The method of reacting a hydrocarbon feed with hydrogen underconditions of temperature, pressure and reaction time in the presence ofadded hydrogen sufficient to react at least a portion of said addedhydrogen with said feed in the presence of a catalyst comprising atleast one crystalline aluminosilicate zeolite and at least onehydrogenation component selected from molybdenum, tungsten, and theGroup VIII metals, oxides and sulfides, at least said one zeolite havingbeen prepared from a large pore zeolite having an average pore size ofat least about 5 angstroms and containing less than about 3 weightpercent alkali metal determined as the corresponding oxide and at leastone cation selected from iron, cobalt, nickel, magnesium, calcium andthe rare earth cations by thermal treatment of said zeolite by at leastone of (a) calcination at a temperature of at least about 1200 F. and(b) steaming at a temperature of at least about 900 F., intimatelycombining the resultant zeolite with said hydrogenation component, andthermally activating the resultant combination of said zeolite and saidhydrogenation component at a temperature of at least about 500 F.

2. The method of claim 1 wherein said hydrocarbon feed boils primarilyabove about 400 F. and is hydrocracked in the presence of said catalystand added hydrogen at a temperature of at least about 500 F. in thepresence of at least 500 standard cubic feet of added hydrogen perbarrel of said feed, said zeolite is selected from zeolites X, Y, L, A,and mordenite and contains at least 0.5 weight percent of said cationprior to said thermal treatment, said cation is at least one of iron,cobalt, nickel, magnesium, calcium, cerium, lanthanum, praseodyminum andneodymium and said hydrogenation component is selected from molybdenum,tungsten, nickel and cobalt metals, oxides and sulfides.

3. The method of claim 2 wherein said zeolite is selected from zeolitesX and Y and said hydrogenation component comprises at least one ofmolybdenum metal, oxide and sulfide.

4. The method of claim 3 wherein said hydrocarbon is hydrocracked in thepresence of said catalyst and hydrogen added in amounts of about 5000 toabout 15,000 standard cubic feet per barrel of said feed at atemperature of about 500 to about 900 !F. and a pressure of about 1000to about 3000 p.s.i.g.

5. The method of claim 2 wherein said hydrocarbon feed contains at leastone of sulfurous and nitrogenous 1 1 1 2 hydrocarbons and said feed isreacted with said hydrogen 3,391,088 7/ 1968 Plank et a1. 252455 Z inthe presence of said catalyst under conditions suliicient 402 9 5 9 9Maher et 1 42 g gf l gg fi gggg fi 2g agg 3,407,148 10/1968 Eastwood eta1. 252-455 2 6. The method of claim 2 wherein said zeolite includes 53,462,377 9/1969 Plank et 252-455 Z zeolite Y, said cation includes atleast one of nickel and 3,293,192 12/1966 M e et a 252-430 cobalt andsaid hydrogenation component includes at least one of molybdenum metal,oxide and sulfide. DELBERT GANTZ Primary Examiner G. E. SCHMITKONS,Assistant Examiner References Cited 10 UNITED STATES PATENTS US. Cl.X.R.

3,197,398 7/1965 Young 208-111 208-DIG. 2; 252-455 Z; 260-683.65

3,352,796 11/1967 Kimberlin et al. 252-455 Z

